1. Field of the Invention
This invention relates to a method and apparatus for continuously transferring material dislodged from a mine face by a continuous mining machine into a shuttle car for removal from the mine, and more particularly to a material transfer apparatus that includes mechanically adjustable roof supports that engage the mine roof and support the roof during the drilling of bolt holes and the installation of roof bolts in the mine roof by roof drilling units that are mounted on the material transfer apparatus.
2. Description of the Prior Art
In the past, it has been the practice in underground mining of coal and other minerals to dislodge a given section of the mine face, for example ten to twenty feet, and then interrupt the mining operation to install wooden pillars and cross members and more recently hydraulic jacks to temporarily support the mine roof. The mining machine was then removed from the face and a roof bolter brought into position for the installation of permanent roof support. Not only was this method of temporarily supporting the mine roof unsafe but it interrupted the mining operation.
More recently, material transferring apparatus, such as disclosed in U.S. Pat. No. 3,456,982, have been developed for receiving material dislodged from the face by a continuous mining machine. The transfer apparatus includes a longitudinal conveyor that remains in material receiving relationship with the continuous mining machine. The material is deposited onto the conveyor and removed from the face as roof bolting equipment carried by the transfer apparatus installs roof bolts in the mine roof immediately behind the advancing mining machine.
U.S. Pat. No. 3,268,258 discloses a material conveying and roof bolting apparatus that includes a self-propelled longitudinal conveyor that is adapted to receive mined material from a continuously advancing mining machine and to perform roof drilling and bolting operations without interrupting the conveying away of the mined materials. The material receiving end portion of the conveyor includes a hopper which underlaps the mining machine conveyor and into which the dislodged material is deposited. The main conveyor then transports the dislodged material rearwardly from the hopper of the discharge end that includes a discharge conveyor arranged to pivot about a vertical and horizontal transverse axis. The discharge conveyor deposits the mined material into mine cars or onto another conveyor for removal from the mine.
Roof drilling and bolting devices are immovably secured to the transfer unit at opposed sides of the conveyor. Each of the drilling and bolting units includes a vertically movable boom that positions the roof drilling and bolting unit adjacent the mine roof for drilling the roof hole and installing a roof bolt in the mine roof.
There is a need to provide a vehicle transfer apparatus that coordinates the operation of the continuous mining machine with the removal of the dislodged material from the mine, and provides temporary support roof as permanent roof support is installed during the mining operation and while the mining machine continues to advance into the mine face. The material should be transferred from the mining machine to a haulage vehicle in such a manner to permit the mining machine to operate without interruption during which time roof bolts are installed in the mine roof and temporary roof support is provided during the roof bolting and continuous mining operations. There is also a need for a continuous mining system where temporary roof support is provided while permanent roof supports are installed during the mining operation and the mining machine operator is protected by either temporary or permanent roof supports during the mining operation.